Exposure to asbestos is generally accepted to be a health hazard. Asbestos materials that tend to become friable are regarded as particularly hazardous because the asbestos becomes easily entrained into the air as the materials deteriorate with age . Concern about health issues and environmental contamination by asbestos has promulgated numerous Federal Regulations dealing with the subject. It has therefore become important to develop ways of eliminating the contamination.
Materials used in roofing for years have contained asbestos The asbestos-containing materials used in roofing are the type that tend to become friable and are unsafe. The friable materials are dealt with by encapsulation or removal.
Encapsulation permits the asbestos-containing material to remain safely in place for longer periods of time than it otherwise could. However, encapsulation represents a temporary measure since sealants also will deteriorate with time.
Because no adequate chemical removal procedures have been developed, removal is accomplished by hand held impact and cutting tools. Asbestos-containing materials tend to pulverize upon impact or scraping rather than shear off in large pieces. Consequently, hand labor requirements are greatly increased and heavy asbestos dust contamination results.
One method of dealing with the dust contamination problems is by a simple wetting operation. Water is sprayed on the asbestos-containing material in order to lower the friability. Water spraying is not a satisfactory solution. At best, water provides a slow, incomplete penetration of the asbestos-containing material. Water run-off may carry asbestos fibers to other areas and increase the safety hazard.
Erzinger, Pat. No. 4,693,755 discloses a method for removing asbestos-containing materials from their substrate. The method includes applying a composition containing a cellulosic polymer such as hydroxypropyl cellulose to the asbestos-containing materials, allowing the cellulosic polymer containing composition time to penetrate and wet the asbestos-containing material, and removing the resulting wet asbestos-containing material by use of mechanical forces.
Tidquist, Pat. No. 4,699,666 discloses a similar method for removing asbestos-containing materials from their substrate. The patent teaches the use of a debilitant composition of water and a homopolymer of ethylene oxide having a molecular weight of from about 100,000 to about 5,000,000 and having a repeating monomeric unit with a molecular weight of 44. The composition is applied to a body of asbestos-containing insulation in sufficient quantity to thoroughly wet at least the exposed portion. The pre-wet body is then mechanically removed.
An objective of the present invention is to provide an improved method and composition for removing asbestos-containing materials.
Another objective of this invention is to provide a method for treating asbestos-containing materials in the removal process that facilitates the use of inexpensive, readily available, non-toxic material.
Still another objective of this invention is to provide a composition having an advantageously low evaporation rate and deep penetration power.
Yet still another objective of this invention is to provide a simple, effective, inexpensive method for treating asbestos-containing materials.
Other objects and advantages will become apparent upon reference to the following detailed discussions.